How to use a Bong Mouthpiece
If you are using this adapter for an actual bong, place the mouthpiece, pointy side down, into the mouthpiece area of the bong. Then push down gently and make sure there is a tight seal between the rubber mouthpiece and the bong. With a tight seal, you are ready to smoke.
If you are using a chillum pipe, a Sherlock or perhaps the popular spoon pipe style, you will place the pointy side of the mouthpiece up against the mouthpiece of your glass piece to create a tight seal. This is not as seamless as using a bong, but it works when done properly.